Areas set aside for the preservation of fauna, flora, and their natural habitats. [Macmillan Encyc., 2001]
Natural resources that are used for heat and power generation, including oil, natural gas, coal, and geothermal energy.
Undomesticated organisms living in natural settings without dependence on man.
Treeless, level, or gently rolling plains characteristic of arctic or subarctic regions, having a permanently frozen subsoil, and usually supporting low growing vegetation such as lichens, mosses, and stunted shrubs. [USGS Circ 1048]